1. Field of the Invention
The present invention relates to an improvement of a copy sheet size inputting and detecting device for an image forming apparatus, such as, for example, a copier, a facsimile machine, a printer, and so on.
2. Discussion of the Background
In the conventional copying apparatus, a copy sheet size is sensed automatically, in a number of ways mentioned below. First, a code indicative of the copy sheet size is labeled to the copy sheet cassette, and the code is read by a sensing device when the cassette is set into the copy machine. Second, a size sensing device is interconnected to a side plate slidably mounted on the copy sheet cassette, and thereby the size is sensed when the side plate is adjusted to the side edge of the copy sheet. Third, a size setting device manually settable by the operator is disposed on the copy sheet cassette, and thereby, the size is recognized by a sensing device disposed in the copy machine when the cassette is set therein.
However, the above mentioned devices each employ an extra sensing means at the copy sheet cassette for sensing the size of the copy sheet accommodated in the copy paper cassette, and thereby the cost is raised.